The black coating you see is a coating of copper oxide, which forms when the hot metal reacts with air. no air can reach the inside, so it does not react to form black copper oxide.
phyllite
If slate is sufficiently heated and compressed it becomes phyllite.
Gneiss.
When copper is heated in oxygen, the compound formed is copper oxide.
When copper carbonate is heated, it changes from its green color to black copper oxide.
When copper sulfate is heated, it decomposes to form copper oxide and sulfur dioxide gas.
When copper carbonate is heated, it decomposes into copper oxide, releasing carbon dioxide gas. The remaining ionic compound is copper oxide (CuO).
Yes, copper expands when heated.
When copper sulfide is heated in the air, it is oxidized to form copper oxide (CuO) and sulfur dioxide (SO2) gas.
Absolutely
Copper sulfate is formed.
Yes, a reaction will occur when copper is heated with iron oxide. The iron in iron oxide will react with the copper to form copper oxide and iron.